#include <REGX52.H>
#include <intrins.h>
void Delay1ms(int x)		//@11.0592MHz
{
	unsigned char i, j;
	while(x--)
	{
		_nop_();
		i = 2;
		j = 199;
		do
		{
			while (--j);
		} while (--i);
	}
}
void main()
{
	unsigned char num=0;
	while(1)
	{
		if(P3_0==0)
		{
			Delay1ms(20);
			while(P3_0==0);
			Delay1ms(20);
			
			P1=~(++num);
			
		}
	}
}